Fix in PDB export

Better add_git_submodule

cmake/AddGitSubmodule.cmake

@@ -10,7 +10,7 @@ function(add_git_submodule dir)
 	# add_git_submodule(mysubmod_dir)
 	find_package(Git QUIET)
 
-	if(NOT EXISTS ${dir}/CMakeLists.txt)
+	if(NOT EXISTS "${PROJECT_SOURCE_DIR}/${dir}/CMakeLists.txt")
 		if(NOT (GIT_FOUND AND IS_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/.git"))
 			message(FATAL_ERROR "${CMAKE_CURRENT_SOURCE_DIR} is not a git repository and the submodule ${dir} is not complete. Cannot continue.")
 		else()

src/pdb/cif2pdb.cpp

@@ -2458,6 +2458,8 @@ void WriteRemark350(std::ostream &pdbFile, const datablock &db)
 
 		auto gen = db["pdbx_struct_assembly_gen"].find1(key("assembly_id") == id);
 
+		if (gen)
+		{
 			std::string asym_id_list, oper_id_list;
 			cif::tie(asym_id_list, oper_id_list) = gen.get("asym_id_list", "oper_expression");
 
@@ -2490,6 +2492,7 @@ void WriteRemark350(std::ostream &pdbFile, const datablock &db)
 						<< std::endl;
 			}
 		}
+	}
 }
 
 void WriteRemark400(std::ostream &pdbFile, const datablock &db)